The long-term objective of research is the identification of the genetic and biochemical determinants of virulence (virulence factors) of Streptococcus mutans, their characterization and the estimation of the efficacy of some cell-surface associated virulence factors as antigens against which immunization may be directed. Using bacteriological, biochemical, immunological and experimental pathology procedures work will be directed at further characterization of glucosyl transferases, glucan linkage patterns, glucan binding sites, glucanohydrolase activity, and other virulence-associated properties of WT organisms and mutants of them defective in those selected traits. Studies will explore the role of these traits in virulence expression and their possible utility in experimental protection of animals against dental caries.